PN532 distance lenght between the IC and antenna coil

[mharmouzi]

Hello everyone,

I'm using the NFC PN532 IC serie, for a project of smart lock which we use two board :

- One contain the IC and others compoents like MCU, ...

- and the other board contain the PCB antenna coil with connector.

I want to connect the two board with a pluging connector (plug to plug connector) i know it should have 50 ohm of target impedance.

My question is about the lenght of the cable for good communication? and the RF matching should be in the coil antenna board or in the other?

best regards.

[KellyLi]

Hello @mharmouzi 

It is recommended that you use a socket to connect directly (plug to plug connector), no cables between connectors which is more reliable. And you're right, the RF matching should be in the coil antenna board.

Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.

Best regards,
Kelly
Technical Support
NXP Semiconductor

[mharmouzi]

Thank you for your anwer Mr. Kelly @KellyLi  i appreciate that, for the cable it is obligatory in our project so we need to u use a 15 cm distance or less for the connection cable, also, if its possbile how can i chose it?

Best regards.

[KellyLi]

Hello @mharmouzi 

The following factors should be considered for your application scenario:
1. Impedance matching
2. Resonant frequency
If the above two points can meet the design requirements, NFC can achieve normal work.

Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.

Best regards,
Kelly
Technical Support
NXP Semiconductor